# -*- coding: utf-8 -*-
# 自定义的分页组件
"""
 以后如果想要使用这个分页组件，你需要做如下几件事

 在视图函数中
 def pertty_list(request):
  # 1.根据自己的情况去帅选自己的数据
  queryset = models.PrettyNum.objects.all()
  2.实例化分页对象
  page_object = Pageiation(request,queryset)

  context = {
    "queryset":page_object.page_queryset  # 分完页的数据
    "page_string":page_object.html()  # 生成页码
  }

  return render(request,'pretty_list.html',context)


"""
from django.utils.safestring import mark_safe


class Pagination(object):
    def __init__(self,request,queryset,page_size =10,page_param="page",plus=5):
        """
        :param request: 请求对象
        :param queryset: 符合条件的数据 (根据这个数据给他进行分页处理)
        :param page_size: 每页显示多少条数据
        :param page_param: 在url中传递的获取分页的参数， /ptty/list/?page=12
        :param plus:  显示当前页的前或后几页 （页码）
        """

        import copy
        query_dict = copy.deepcopy(request.GET)
        query_dict._mutable = True
        self.query_dict = query_dict
        self.page_param = page_param

        page = request.GET.get(page_param,"1")
        if page.isdecimal():
            page = int(page)
        else:
            page = 1

        self.page = page
        self.page_size = page_size

        self.start = (page - 1)*page_size
        self.end = page * page_size

        self.page_queryset = queryset[self.start:self.end]

        total_count = queryset.count()
        total_page_count,div = divmod(total_count,page_size)
        if div:
            total_page_count += 1
        self.total_page_count = total_page_count
        self.plus = plus


    def html(self):
        # 计算出，显示当前页的前5页，后5页
        if self.total_page_count <= 2* self.plus +1:
            # 数据库中的数据比较少，都没有达到11页
            start_page = 1
            end_page = self.total_page_count
        else:
            # 数据库中的数据较多 》11页
            # 当前页《5页时
            if self.page <= self.plus:
                start_page = 1
                end_page = 2 * self.plus +1
            else:
                # 当前页 > 5
                # 当前页+5 >总页数
                if(self.page + self.plus) > self.total_page_count:
                    start_page = self.total_page_count - 2 * self.plus
                    end_page = self.total_page_count
                else:
                    start_page = self.page - self.plus
                    end_page = self.page + self.plus

        # 页码
        page_str_list = []
        self.query_dict.setlist(self.page_param,[1])
        page_str_list.append('<li ><a href="?{}">首页</a></li>'.format(self.query_dict.urlencode()))
        # 上一页
        if self.page > 1:
            self.query_dict.setlist(self.page_param, [self.page - 1])
            prev = '<li ><a href="?{}">上一页</a></li>'.format(self.query_dict.urlencode())
        else:
            self.query_dict.setlist(self.page_param, [1])
            prev = '<li ><a href="?{}">上一页</a></li>'.format(self.query_dict.urlencode())
        page_str_list.append(prev)

        # 页面
        for i in range(start_page, end_page + 1):
            self.query_dict.setlist(self.page_param, [i])
            if i == self.page:
                ele = '<li class="active"><a href="?page={}">{}</a></li>'.format(self.query_dict.urlencode(), i)
            else:
                ele = '<li><a href="?{}">{}</a></li>'.format(self.query_dict.urlencode(), i)
            page_str_list.append(ele)

            # 下一页
        if self.page < self.total_page_count:
            self.query_dict.setlist(self.page_param, [self.page+1])
            prev = '<li ><a href="?{}">下一页</a></li>'.format(self.query_dict.urlencode())
        else:
            self.query_dict.setlist(self.page_param, [self.total_page_count])
            prev = '<li ><a href="?{}">下一页</a></li>'.format(self.query_dict.urlencode())

        page_str_list.append(prev)

        # 尾页
        self.query_dict.setlist(self.page_param, [self.total_page_count])
        page_str_list.append('<li ><a href="?{}">尾页</a></li>'.format(self.query_dict.urlencode()))

        search_string = """
                <li>
                    <form style="float: left;margin-left: -1px" method="get" >
                        <input type="text" name="page" style="position: relative;float: left;
                             display: inline-block;width: 88px; border-radius: 0;" class="form-control" placeholder="页码">
                        <button style="border-radius: 0" class="btn btn-default" type="submit">跳转</button>
                    </form>
                 </li>
            """
        page_str_list.append(search_string)

        page_string = mark_safe("".join(page_str_list))

        return page_string




